As the network and services becomes complex, people need better management and monitoring of the network operation and transmitted content. Firstly, from the point of services, the increasing trend of service diversity, makes differentiating quality of services (QoS) requirements a challenge. Network should try to meet the QoS requirements of the services, but the premise is to get and analyze QoS. This requires us to perform online service classification, in order to classify the different services during transmission effectively, groom the traffic in accordance with the established strategy, and measure the services performance of application layer and complete user billing. Secondly, from the point of network planning and optimization, network administrators need to analyze the component of existing traffic, in order to optimize the existing network structure or plan new network construction. The latter does not require online identification methods, which can be analyzed with offline manner. In addition, from the point of network security, we need to wipe out the harmful traffic such as the worms and restrain its spread, which also need traffic identification technology as a support.
Existing traffic identification technology is mainly based on the transport layer port and application layer payload (signature). Since the abuse of the port number, especially P2P service uses dynamic ports or even use port 80 of HTTP protocol as transmission channel, make the application identification method based on the transport layer port lose its effectiveness. Since the method which is based on the application layer payload involves more complex operations, it is not suitable for high-speed backbone network traffic identification. Because of computational complexity and the inherent features of serial processing, the traffic identification method with artificial intelligence is not suitable for hardware implementation of network equipment, which limits its application in high-speed backbone network.
In order to meet the current and future needs of high-speed backbone network, traffic identification technology urgently needs the following requirements: 1) avoid using the port or payload as the main identification features when choosing parameters; 2) enable online identification when design the algorithms; 3) use the processing method that has the features of parallel processing and is easy to implement on the hardware.